The present invention relates to an electronic circuit system unit. The present invention, in particular, relates to an electronic circuit system unit having a semiconductor integrated circuit unit formed on a wafer scale, in which a plurality of integrated circuit blocks are disposed on a circuit mounting surface of a semiconductor wafer (WSI: Wafer Scale Integration).
There is a tendency to use a semiconductor storage circuit unit formed on a wafer scale (WSM: Wafer Scale Memory) for a memory unit to be used as a main storage unit to be incorporated in computer systems such as personal computers (PC) or workstations (WS). An example semiconductor storage circuit unit formed on a wafer scale is described in U.S. Pat. No. 4,484,215. A semiconductor storage circuit unit formed on a wafer scale has no mechanical parts, it is possible to make the information writing speed or the information reading speed faster as compared to a magnetic disk memory, which has been the commonly used main storage memory unit. Also, a semiconductor storage circuit unit formed on a wafer scale can make the mounting area small when incorporated in a computer system.
In a semiconductor storage circuit unit formed on a wafer scale, a plurality of storage circuit units (each corresponds to a semiconductor pellet) are disposed systematically on a circuit mounting surface of a semiconductor wafer formed with a silicon monocrystal. The storage circuit unit corresponds to one track of a magnetic disk of a magnetic disk memory, and constitutes a memory unit which is able to store information of a specified capacity. In the case of a semiconductor storage circuit unit formed on a wafer scale, a higher mounting density can be obtained as compared to a plurality of semiconductor units (for example, assembled package products, SOP, ZIP, etc.). With the latter, semiconductor pellets having storage circuits corresponding to the above-mentioned storage circuit units are sealed up with a sealing material and mounted on a printed wiring substrate (PCB).
A semiconductor storage circuit unit formed on a wafer scale is mounted on a surface of a printed wiring substrate as a memory unit. A plurality of terminals (bonding pads) are disposed in the peripheral area on a circuit mounting surface of a semiconductor wafer of the wafer scale semiconductor storage circuit unit. The plurality of terminals are electrically connected with wires to a plurality of respective terminals disposed in corresponding positions on a surface of a printed wiring substrate.
A semiconductor storage circuit unit formed on a wafer scale is mounted on an outer peripheral surface of a print wiring substrate, and a plurality of memory driver units are mounted on a surface of the print wiring substrate. Each memory driver unit comprises a semiconductor unit (assembled package product) in which a semiconductor pellet mounted with an integrated circuit corresponding to a circuit mounting surface is sealed in with a sealing material. A wafer scaled memory as such, for example, is disclosed in ISSCC (International Solid-State Circuits Conference), Digest of Technical Papers, 1989, pp. 240-241, 350.